Melt-processible, wear resistant polyethylene

Abstract

Melt-processible, thermoplastic polyethylene compositions of high resistance against wear are disclosed and methods for making and processing same. Additionally, products comprising these compositions are described.

1 . Polyethylene having:
 a weight average molecular weight in the range of 150,000-1,000,000 g/mol;   a number average molecular weight of at least 25,000 g/mol;   a polydispersity in the range of 1.3-10; and   a wear coefficient of less than 3.2 10 −4  mm 3 /mN.   
   
   
       2 . The polyethylene of  claim 1 , wherein said polyethylene has a wear coefficient below 2.9 10 −4  mm 3 /mN. 
   
   
       3 . Polyethylene having:
 a melt viscosity of less than 10 6  Pa·s; and   a wear coefficient below 2.4 10 −4  mm 3 /mN.   
   
   
       4 . The polyethylene according to  claim 1 , wherein said polyethylene has a weight average molecular weight below 700,000. 
   
   
       5 . The polyethylene according to  claim 1 , wherein said polyethylene has a weight average molecular weight below 500,000. 
   
   
       6 . The polyethylene according to  claim 1 , wherein said polyethylene has a weight average molecular weight of at least 250,000. 
   
   
       7 . The polyethylene according to  claim 1 , wherein said polyethylene has a co-monomer content of less than 10 mol %. 
   
   
       8 . The polyethylene according to  claim 1 , wherein said polyethylene has a co-monomer content in the range of 0.5-5 wt %. 
   
   
       9 . The polyethylene according to  claim 1 , wherein said polyethylene has a wear coefficient below 2.0 10 −4  mm 3 /mN. 
   
   
       10 . The polyethylene according to  claim 1 , wherein said polyethylene has a polydispersity below 5. 
   
   
       11 . The polyethylene according to  claim 1 , wherein said polyethylene has a polydispersity in the range of 2-4. 
   
   
       12 . The polyethylene according to  claim 1 , wherein said polyethylene has a melting point of at least 100° C. 
   
   
       13 . The polyethylene according to  claim 1 , wherein said polyethylene has a melt viscosity of less than 5·10 5  Pa·s. 
   
   
       14 . The polyethylene according to  claim 1 , wherein said polyethylene has a number average molecular weight of at least 100,000 g/mol. 
   
   
       15 . A process comprising melt-processing the polyethylene according to  claim 1 . 
   
   
       16 . The process of  claim 15 , wherein said process includes injection molding said polyethylene. 
   
   
       17 . An article obtainable by the process according to  claim 15 . 
   
   
       18 . An article comprising the polyethylene according to  claim 1 . 
   
   
       19 . Use of the polyethylene according to  claim 1 . 
   
   
       20 . A sliding member comprising a polyethylene, said polyethylene having:
 a weight average molecular weight below 1,000,000 g/mol; and   a wear coefficient of less than 3.2 10 −4  mm 3 /mN.